<template>
  <div class="star" :class="'star-'+size">
    <span class="star-item on" v-for="(sc, index) in starClasses" :key="index" :class="sc"></span>
  </div>
</template>
<script>
//类名常量
const CLASS_ON = 'on';
const CLASS_HALF = 'half';
const CLASS_OFF = 'off';
export default {
  name: "",
  data() {
    return {};
  },
  props: {
    score: Number,
    size: Number
  },
  methods: {},
  computed:{
      starClasses(){
          /**
           * 3.2: 3+0+2
           * 3.5: 3+1+2
           */
          const {score} = this;
          let scs = [];
          //向scs中添加n个CLASS_ON
          let scoreInteger = Math.floor(score);
          for(let i =0;i<scoreInteger;i++){
              scs.push(CLASS_ON);
          }
          //向scs中添加0/1个CLASS_HALF 浮点数计算不j精确
           if((score*10-scoreInteger*10)>=5){
               scs.push(CLASS_HALF);
           } 
          //向scs中添加n个CLASS_OFF
          while(scs.length<5){
              scs.push(CLASS_OFF);
          }
          return scs;
      }
  }
};
</script>
<style  lang='stylus' rel='stylesheet/stylus'>
@import '../../common/stylus/mixins.styl';

.star { // 2x图 3x图
  float: left;
  font-size: 0;

  .star-item {
    display: inline-block;
    background-repeat: no-repeat;
  }

  &.star-48 {
    .star-item {
      width: 20px;
      height: 20px;
      margin-right: 22px;
      background-size: 20px 20px;

      &:last-child {
        margin-right: 0;
      }

      &.on {
        bg-image('./images/star48_on');
      }

      &.half {
        bg-image('./images/star48_half');
      }

      &.off {
        bg-image('./images/star48_off');
      }
    }
  }

  &.star-36 {
    .star-item {
      width: 15px;
      height: 15px;
      margin-right: 6px;
      background-size: 15px 15px;

      &:last-child {
        margin-right: 0;
      }

      &.on {
        bg-image('./images/star36_on');
      }

      &.half {
        bg-image('./images/star36_half');
      }

      &.off {
        bg-image('./images/star36_off');
      }
    }
  }

  &.star-24 {
    .star-item {
      width: 10px;
      height: 10px;
      margin-right: 3px;
      background-size: 10px 10px;

      &:last-child {
        margin-right: 0;
      }

      &.on {
        bg-image('./images/star24_on');
      }

      &.half {
        bg-image('./images/star24_half');
      }

      &.off {
        bg-image('./images/star24_off');
      }
    }
  }
}
</style>